Electric outlet box



March 7, 1939. H. L, ARNEs'r 2,149,719.

l n ELECTRIC OUTLET BOX Filed Aprills, 1937 aman' Patented Mar. 7, 1939 UNITED STATES PATENT oFFlCE ELECTRIC OUTLET BOX Harry L. Arnest, Arlington, Va.

Application April 13, 1937, Serial No. 136,677

4 claims. v(c1. 22o-3.4) Y

This invention relates to house wiring elements and more especially to electric outlet boxes such as are commonly employed as receptacles for plugs, switches and the like at the points where such plugs, switches, etc. are exposed at the face of a wall.

The coventional types of outlet boxes are provided with out-turned lugs or ears for the reception of screws which pass through and bind the straps (which support the plugs or switches, as the case may be) to said ears. It is the usual practice to make these screws quite long to take care of the varying conditions which are met with in installing the switches, etc.

The threads upon these screws are comparatively lne, and a great deal of time and effort is expended by the electrician in putting one of these screws in place. When it is reflected that an electrician may have to put hundreds of these screws in place upon a single job, the resultant loss of time and the greatly increased labor will be better appreciated.

It is the primary object of the present invention to provide an electrical outlet box or equivalent article with screw engaging means of such a nature that the screw may be merely pushed endwise, and without turning, through said means and'may then be tightened by being turned with a screw driver in the usual way. In the accompanying drawing, I have illustrated two ways in which this object may be accomplished, though as the description proceeds it' will be apparent that many other ways will readily suggest themselves to those skilled in the art. Y It is a further and important object of the invention to so construct the screw engaging unit as to cause it to constitute a shield to prevent the plaster from passing to a place where it will prevent the proper operation of the screw. Further objects and advantages will be set. forth in the detailed description which follows.

In the accompanying drawing, wherein like numerals designate corresponding parts throughout the several figures: Y

Figure 1 is a fragmentary perspective view of a portion of an outlet box having the invention applied thereto;

Fig. 2 is a transverse sectional view through the screw holding mechanism hereinafter described;

Fig. 3 is a view like Fig. 2 but upon an enlarged scale;

Fig. 4 is a detail perspective view of one form of detent member which may be employed;

Fig. 5 is a fragmentary sectional view showing the screw housing hood and the detents for the screw, integral with the box and struck from the metal of which the top of the box is made, and

Fig. 6 is a sectional view upon line 6-6 of Fig. 5.

In the drawing, 5 designates the sides and 6 the top or one end of a conventional electrical outlet box. It is common practice to provide these outlet boxes with lath-engaging ears 1, the

lath being indicated at B and the plaster at 9 in Fig. 2.

Instead of providing a threaded lug for the reception of the holding screw I0, by which the strap II of a plug assembly I2 is secured to the outlet box, I provide a lug I3 having a. nonthreaded opening therein oi such size that the screw I0 may be thrust endwise therethrough. When so thrust inwardly, the screw passes through a sleeve I I and is engaged by any suitable type of spring detent which will permit the endwise thrusting of the screw thereby and will engage said screw in such fashion that when the rscrew is turned with the screw driveryit will be fed further inwardly by the action of its threads in their engagement with said detents to bring about a very tight and secure binding of the strap I I against the face of the lug I3.

In Figs. 2, 3 and 4, I have illustrated the spring detents as being in the form of thimbles comprising cylindrical portions I5 and split frustoconical portions I6, the splitting of these portions creating a` series of spring ngers I'I which engage the threads of the screw at such an angle as to permit the screw to be thrust endwise thereby in one direction but to resist movement of the screw in the other direction.

These thimbles` I5 may be in any desired number and may be slipped endwise into the sleeve I4. Any suitable means may be provided for holding these thimbles against outward movement from y the sleeve, as for example, by indenting the metal of the sleeve, as indicated at I8. The sleeve may be spot-welded or otherwise secured to the lug I3- or to the top of the box.

The sleeve I4 is extended inwardly far enough beyond the lath-engaging ear 1 to prevent the bottom lath from overlapping and closing up the inner end of the sleeve. In this case, the lowermost lath would rest upon the top of the sleeve and, if desired, could be cut out for engagement over said sleeve.

With this arrangement, it will be seen that the plaster cannot enter the sleeve and cannot interfere in any way with the proper operation of the holding screw III. Under the arrangement at present in use, the electricians have a great deal of trouble in getting the screws in place, because the plasterer iills the space between the lath and the lug, corresponding to lug I3, with plaster, and the electricians have a great deal of trouble punching through this plaster for the passage of the screws.

Further, where a considerable length of time has elapsed `between the time that the plaster was applied and the time that the electrician comes back on the job to put in the plugs and switches and apply the cover plates, the electrician frequently iinds that the threads in the lugs of the outlet box have become so rusted from the moisture of the plaster that it is difcult to get the screws into them.

These screws are comparatively small and are not very strong, and it is frequently the case that they wring oi when the electrician tries to force them through the rusty threads of the lugs. When that happens, it involves a tap-out job, frequently'in a very inconvenient and awkward place to get at. All of this trouble is avoided by the device of the present invention.

In the form of the invention illustrated in Figs. 5 and 6, I have shown the spring detents and a housing corresponding to sleeve I4 as being made integral with and struck from the metal of the top of the box.

In this form of the invention, 6a, represents the top of the box and corresponds to the top 6 of Fig. 1. The metal is struck upwardly to form a vertical portion I3a, corresponding to lug I3, and is then bent inwardly to form a hood Ida, corresponding to sleeve I4. The sides of this hood are bent downwardly to lie close to the top Ii'a.

Spring detent fingers 20 are struck upwardly from the box top, and corresponding spring ngers 2| are struck downwardly from the hood Illa to engage the threads of the screw in the same manner as describedl with respect to iingers I'I. While this leaves some small openings in the top of the hood I4, these are hardly large enough to permit the entry of any appreciable amount of plaster, but if desired, the electrician could paste a small paper sticker over these openings whenhe leaves the job after roughing in and before the time of application of screws Illa to permit entry of plaster.

While this arrangement of electric outlet box, spring detents and screw adapted to be thrust endwise through said detents is of particular use in the relation described and especially so when the device is caused to serve the double function of a plaster excluding element and a screw engaging structure, it is a fact that the device is also of great usefulness in mounting other wallcarried electrical appliances.

For example, in hanging electric fixtures, involving the use of canopies, the electrician uses relatively long screws so that he can keep the canopies away from the wall far enough for him to peep in and locate the hole into which the screw is to be inserted.

However, this involves considerable screw driver manipulation in order to take up all this long length of thread after he has started the screw and has shoved the canopy up against the wall. It is clear that under these conditions, a screw which could be thrust into engagement with thread engaging members by a mere endwise thrust and thereafter tightened by only a turn or two with a screw driver would save a` great deal of time and work.

While I have shown the spring detent carrying element as being xed to the outlet box, it will Vbe apparent that all that is necessary is that xed detents be arranged in conjunction with the box, whether secured directly to the box or to any other part. For example, the sleeve I4 and the spring detent elements could be carried by the ear l or any other part, so long as this sleeve was disposed in plaster excluding position and receive the screw as described.

Consequently, it is to be understood that the invention includes within its purview whatever changes fairly come within either the terms or the spirit of the appended claims.

Having described my invention, what I claim 1s:

1. In an electric outlet box, a holding screw, a plaster excluding hood rigidly aixed to the outlet box, and a detent in said hood engaging the screw in such manner as to permit the direct endwise thrusting of the screw past said detent while resisting reverse endwise movement of the screw, said detent engaging the threads of the screw in such manner that turning of the screw will impart a final tightening thereto.

2. The combination with an electric outlet box of a plaster excluding hood aflixed to said outlet box, a part to be held in said box, a screw adapted to traverse said part, and a plurality of spring detents in said hood engaging the threads of said screw in such manner as to permit the screw to be thrust directly inward past said detents and engaging the threads of the screw in such manner as to resist direct endwise movement outwardly, turning movement of the screw in the usual way eiecting an inward feeding of the screw by the engagement of the threads therewith to effect a iinal tightening of the screw under such turning movement.

3. In combination, an outlet box, an outstanding lug carried by the box which lies close to the plaster when in use, a plaster excluding hood, a holding screw, and a detent in said hood comprising a split frustoconica1 thimble of resilient material, as and for the purposes set forth.

4. An electric outlet box having a part integral therewith, the metal being struck out in such fashion as to constitute a plaster excluding hood and spring detent fingers, and a screw adapted to be thrust endwise past said ngers and to have its threads engaged by said ngers, as and for the purposes set forth.

HARRY L. ARNEST. 

